An electronic toll collecting system automatically collects tolls by wireless communications between tollgates and vehicles on toll roads. This system allows vehicles to pay a toll keeping on driving and thus free from stopping at a tollgate. Therefore, this system can save manpower and alleviate traffic jam.
An authorization system for authorizing a vehicle by an IC card is available as one of these electronic toll collecting systems. The following elements make up the authorization system overall:
an IC card; PA1 an in-vehicle-device for reading the IC card and processing the information; and PA1 an on-road apparatus mounted to a tollgate. The on-road apparatus automatically collects tolls by communicating data to a central processing unit (CPU) in an operation center.
When the IC card is inserted into a slot of the in-vehicle-device, the card and device try to authorize each other. When a code stored in the in-vehicle-device agrees with a code stored in the IC card, an authorization is established and the IC card authorizes the in-vehicle-device.
On the other hand, the in-vehicle-device can also authorize the IC card, and detects an agreement of the codes. The device detecting the code agreement communicates the on-road apparatus to authorize each other. When the respective codes agree with, they can authorize each other. Then the on-road apparatus starts communicating the CPU in the operation center about automatic toll collection.
When the code of IC card does not agree with the code of in-vehicle-device, although the in-vehicle-device and on-road apparatus authorize each other, the in-vehicle-device and the IC card cannot authorize each other.
As such, the conventional authorization system requires two-step authorizations i.e. the on-road apparatus authorizes the in-vehicle-device, and the device authorizes the IC card, and these three elements should store the code in common with them. Therefore, if one of the on-road apparatus, in-vehicle-device, or IC card has a code different from the common code, the authorization cannot be established among them.